Field of the Invention
The present invention relates to a fiber-containing polymer film and a method of manufacturing the same, and an electrochemical device and a method of manufacturing the same.
Related Background Art
While an electrolytic solution infiltrated in a separator made of a polyolefin-based stretched porous film or the like has typically been used as an electrolyte for lithium-ion secondary batteries, studies of solid or gelled polymer solid electrolytes (SPE) using a polymer in an electrolytic material have been under way.
Known examples of polymer solid electrolytes for polymer lithium-ion secondary batteries include (i) a gel polymer type; (ii) a composite film made of ceramics and a polymer; (iii) one in which a gel polymer is formed on a nonwoven or stretched film; and (iv) one in which a mixture of a polymer and ceramics is formed on a nonwoven or stretched film. Among them, those of type (iii) in which a gel polymer is formed on a nonwoven or stretched film has been in use for many products.
Improvements in strength of polymer solid electrolytes at high temperatures have also been under study. Specifically, methods mixing ceramic particles and fibrous bodies into a polymer (see, for example, Japanese Patent Application Laid-Open Nos. 2000-173655, 2006-128095, and 03-046213), methods using nonwovens or porous bodies as aggregates (see, for example, Japanese Patent Application Laid-Open Nos. 11-260336 and 11-219727), and the like have been under study.